Hydrogen Storage and Transportation Using Ammonia

Abstract

Hydrogen can be stored in many different forms as compressed or liquefied hydrogen in tanks, as a hydrogen-absorbing alloy, as metal hydrides with light elements, as organic hydrides or by adsorption on carbon materials. Ammonia has been expected as a hydrogen energy carrier because it has a high H2 storage capacity with 17.8 wt and 10.7-12.1 kgH2100 L. The volumetric hydrogen density is 1.5-2.5 times of liquid hydrogen, and it is easily liquefied under about 1 MPa at room temperature. Ammonia has advantages in cost and convenience as a hydrogen carrier for fuel cell vehicles, energy carrier for solid oxide fuel cell (SOFC), gas turbine of electric power plants. Current PEM fuel cells are poisoned by trace levels (0.1 ppm) of ammonia. After hydrogen generation by ammonia cracking, ammonia absorption materials will be useful to produce the high purity hydrogen gas.